This application is based upon, claims the benefit of priority of, and incorporates by reference the contents of prior Japanese Patent Applications No. 2001-372916 filed on Dec. 6, 2001, and No. 2002-187766 filed on Jun. 27, 2002.
1. Field of the Invention
The present invention relates to an air conditioning system for air conditioning the passenger compartment of a vehicle.
2. Description of the Related Art
In General, the air conditioning system for a vehicle proposed in Japanese National Publication No. Hei. 10-504977 has been known as a vehicle air conditioning system having a room air conditioner unit for air conditioning the passenger compartment and a seat air conditioner unit for adjusting the temperature of the seat. The conventional system described in this publication is configured to detect the temperature of the air surrounding the driver or a passenger (hereinafter, referred to simply as the passenger) and the temperature of air inside the seat, and automatically adjust the temperature of the seat by the seat air conditioner unit. In this case, the seat air conditioner unit adjusts the temperature of the seat independently of the room air conditioner unit.
Also, another conventional system described in Japanese Patent Laid-Open Publication No. Hei. 10-297243 performs control in such a manner that the room air conditioner unit and the seat air conditioner unit correlate with each other on the basis of the compartment temperature, an amount of illumination of sunlight, etc. The first-mentioned conventional system, however, has a problem that because the seat air conditioner unit controls the temperature independently of the room air conditioner unit, a difference in heat sensation is caused between the front and the back of the passenger, due to which the passenger may have an uncomfortable feeling.
To be more specific, in the summertime, the room air conditioner unit cools the entire passenger compartment whereas the seat air conditioner unit directly cools the back of the passenger. Hence, the back of the passenger cools more rapidly than the front and a considerable difference in heat sensation is caused between the front and the back of the passenger, due to which the passenger may have an uncomfortable feeling. Conversely, if the control is performed so as to force air conditioning air toward the passenger intensively, the front of the passenger is cooled more rapidly than the back, and this also causes a significant difference in heat sensation between the front and the back of the passenger. Further, in the wintertime, the room air conditioner unit heats the entire passenger compartment, whereas the seat air conditioner unit directly heats the back of the passenger. Hence, the back of the passenger heats more rapidly than the front, and a considerable difference in heat sensation is caused between the front and the back of the passenger.
Alternatively, the second-mentioned conventional system performs control in such a manner that the room air conditioner unit and the seat air conditioner unit have a correlation with each other. However, the heat sensation of the passenger is estimated from information, such as the compartment temperature and the amount of sunlight, which makes it impossible to estimate heat sensations at specific locations such as the front and the rear of the passenger. Hence, this system also cannot eliminate the uncomfortable feeling a passenger may have due to a difference in heat sensations between the front and the rear of the passenger.
The present invention was devised in view of the foregoing, and therefore, has an object to improve the comfortableness of the passenger compartment by reducing a difference in heat sensations between the front and the rear of the passenger.
In order to achieve the above and other objects, a first aspect of the invention provides an air conditioning system for a vehicle furnished with: a room air conditioner unit (1) for air conditioning a passenger compartment; a seat air conditioner unit (2) for adjusting a temperature of a seat (3); a temperature sensor (5) for detecting a temperature at the front of a passenger seated on the seat (3) and the temperature of the seat (3); and a control unit (4) for controlling operation of at least one of the room air conditioner unit (1) and the seat air conditioner unit (2) so that a difference between the temperature at the front of the passenger and the temperature of the seat (3) falls within a certain value range. When the air conditioning system is configured in this manner, a difference in heat sensations between the front and the rear of the passenger is reduced, and hence the comfortableness of the passenger compartment can be improved.
When the first aspect is implemented, according to a second aspect of the invention, an infrared sensor including an element for detecting the temperature at the front of the passenger and an element for detecting the temperature of the seat (3) may be adopted as the temperature sensor (5).
According to a third aspect of the invention, the temperature sensor is composed of a sensor for detecting the temperature at the front of the passenger and a sensor for detecting the temperature of the seat (3) at a location in contact with a back of the passenger.
When the air conditioning system is configured in this manner, the temperature at a portion in contact with the back of the passenger is detected, and heat sensations at the back of the passenger can be accurately detected, which allows more appropriate control to be performed. Hence, the comfortableness of the passenger compartment can be further improved.
According to a fourth aspect of the invention, the seat air conditioner unit (2) includes a blower (21) for blowing air away from the seat (3), and an air-quantity regulating means (25) for regulating a quantity of air blown away from a right side of the seat (3) and a quantity of air blown away from a left side of the seat (3). Also, the temperature sensor (5) is a sensor capable of detecting a temperature at a right front of the passenger and a temperature at a left front of the passenger. Further, the control unit (4) controls operation of the air quantity regulating means (25) based on the temperature at the right front of the passenger and the temperature at the left front of the passenger.
When the air conditioning system is configured in this manner, for example, in the event that the direction and a quantity of sunlight cause a temperature difference between the right front and the left front of the passenger, a local difference in heat sensation due to sunlight or the like can be reduced by adjusting a quantity of air blown from the right side and a quantity of air blown from the left side of the seat on the basis of the temperature difference. Hence, the comfortableness of the passenger compartment can be further improved.
A fifth aspect of the invention provides an air conditioning system for a vehicle furnished with: a room air conditioner unit (1) for air conditioning a passenger compartment and an air-conditioned condition detecting means (5) for detecting an air-conditioned condition at a front location of a passenger seated on a seat (3) and an air-conditioned condition at a contact surface of the passenger with the seat (3). The operation of the room air conditioner unit (1) is controlled so that a difference between two detected values respectively indicating the air-conditioned conditions falls within a certain value range. When the air conditioning system is configured in this manner, even in an air conditioning system having no seat air conditioner unit, a difference in heat sensation between the front and the back of the passenger is reduced, and hence the comfortableness of the passenger and the passenger compartment is improved.
A sixth aspect of the invention provides an air conditioning system for a vehicle furnished with: a room air conditioner unit (1) for air conditioning a passenger compartment; a seat air conditioner unit (2) for adjusting a temperature of a seat (3); and an air-conditioned condition detecting means (5) for detecting an air-conditioned condition at a front location of a passenger seated on the seat (3) and an air-conditioned condition on a contact surface of the passenger with the seat (3). The direction of air blown from the room air conditioner unit (1) is controlled so that a difference between two detected values respectively indicating the air-conditioned conditions falls within a certain value range.
When the air conditioning system is configured in this manner, a difference in heat sensation between the front and the back of the passenger is reduced, and hence the comfortableness of the passenger compartment can be improved.
According to a seventh aspect of the invention, one of a skin temperature of the passenger and heat sensation of the passenger estimated from the skin temperature of the passenger may be used as the two detected values respectively indicating the air-conditioned conditions.
According to an eighth aspect of the invention, the skin temperature of the passenger may be determined based on the temperature of the clothes the passenger is wearing and the temperature of the seat (3).
According to a ninth aspect of the invention, an infrared sensor (5) for detecting the temperature of the clothes the passenger is wearing and the temperature of the seat (3) may be used as the air-conditioned condition detecting means.
According to a tenth aspect of the invention, the infrared sensor (5) may include an element for detecting the temperature of the clothes the passenger is wearing and an element for detecting the temperature of the seat (3).
According to an eleventh aspect of the invention, the certain value to be compared with the difference between the two detected values respectively indicating the air-conditioned conditions changes in response to an air-conditioned condition in the passenger compartment.
When the air conditioning system is configured in this manner, by increasing the certain value when the air-conditioned condition in the passenger compartment is in transition, for example, the uncomfortable feeling the passenger may have due to a difference in heat sensation between the front and the back of the passenger can be reduced while maintaining a time necessary to reach the target room temperature. Also, by decreasing the certain value when the air-conditioned condition in the passenger compartment is stable, infants or elderly people with suppressed temperature-controlling functions feel comfortable because the stress they may feel is lessened.
According to a twelfth aspect of the invention, the certain value to be compared with the difference between the two detected values, respectively indicating the air-conditioned conditions, is set for each seat.
When the air conditioning system is configured in this manner, even in the event that the air conditioning heat load varies from seat to seat due to the influence of sunlight, for example, it is possible to perform the control best suited to each seat by setting the certain value for each seat.
According to a thirteenth aspect of the invention, the certain value to be compared with the difference between the two detected values, respectively indicating the air-conditioned conditions, is set by each passenger. When the air conditioning system is configured in this manner, control can be performed according to each passenger""s desire.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.